Picture codec and teleconference terminal equipment

• US 6,285,391 B1
• Filed: 04/27/2000
• Issued: 09/04/2001
• Est. Priority Date: 07/15/1991
• Status: Expired due to Fees

• Current Assignee: Hitachi, Ltd.
• Original Assignee: Hitachi, Ltd.
• Inventors: Yamada, Takehiko, Matsushima, Hitoshi, Yoshikawa, Hiroshi, Takizawa, Masaaki, Maruyama, Yukinobu, Shibata, Yoji, Ebihara, Toru, Furuya, Jun, Yoshida, Atsuo
• Primary Examiner(s): Chan, Wing F.
• Application Number:
  US09/559,357
• Time in Patent Office: 495 Days
• Field of Search: 348/14.01, 348/14.08, 348/14.1, 348/14.14, 348/14.15, 348/14.07, 379/93.01, 379/93-5-, 379/93.17, 379/93.21, 379/202, 379/201, 379/90.01, 358/400, 358/479, 358/487
• US Class Current: 348/14.07
• CPC Class Codes: G06T 1/20 Processor architectures; Processor configuration, e.g. pipelining
• CPC Class Codes: G06T 9/00 Image coding bandwidth or redundancy reduction for static pictures H04N1/41; coding or decoding of static colour picture signals H04N1/64; methods or arrangements for coding, decoding, compressing or decompressing digital video signals H04N19/00
• CPC Class Codes: H04N 1/1004 using two-dimensional electrical scanning, e.g. cathode-ray tubes using two-dimensional arrays H04N1/195
• CPC Class Codes: H04N 1/42 Systems for two-way working , e.g. conference systems H04N1/32 takes precedence
• CPC Class Codes: H04N 5/45 Picture in picture , e.g. displaying simultaneously another television channel in a region of the screen
• CPC Class Codes: H04N 7/141 between two video terminals, e.g. videophone telephonic communication systems combined with television receiver for reception of entertainment or information matter H04M11/085
• CPC Class Codes: H04N 7/142 Constructional details of the terminal equipment, e.g. arrangements of the camera and the display
• CPC Class Codes: H04N 7/147 Communication arrangements, e.g. identifying the communication as a video-communication, intermediate storage of the signals selecting H04Q
• CPC Class Codes: H04N 7/148 Interfacing a video terminal to a particular transmission medium, e.g. ISDN
• CPC Class Codes: H04N 7/15 Conference systems
• CPC Class Codes: H04Q 11/0457 Connection protocols
• CPC Class Codes: H04Q 11/0471 Terminal access circuits
• CPC Class Codes: H04Q 2213/13034 A/D conversion, code compression/expansion
• CPC Class Codes: H04Q 2213/13091 CLI, identification of calling line
• CPC Class Codes: H04Q 2213/13096 Digital apparatus individually associated with a subscriber line, digital line circuits
• CPC Class Codes: H04Q 2213/13106 Microprocessor, CPU
• CPC Class Codes: H04Q 2213/13175 Graphical user interface [GUI], WWW interface, visual indication
• CPC Class Codes: H04Q 2213/13176 Common channel signaling, CCS7
• CPC Class Codes: H04Q 2213/13179 Fax, still picture
• CPC Class Codes: H04Q 2213/13204 Protocols
• CPC Class Codes: H04Q 2213/13209 : ISDN
• CPC Class Codes: H04Q 2213/1332 : Logic circuits
• CPC Class Codes: H04Q 2213/13337 : Picturephone, videotelephony
• CPC Class Codes: H04Q 2213/204 : ISDN protocol; ISO 7
• CPC Class Codes: H04Q 2213/337 : Picturephone

Abstract

In a teleconference terminal equipment; a picture codec for simultaneously displaying a still picture and video on a single screen, comprising an analog-to-digital converter which converts a picture signal into digital picture data, a picture-in-picture processor which is supplied with the digital picture data as self-picture data of the terminal equipment, a video decoder or a still picture decoder which decodes input picture data and delivers the decoded data to the P-in-P processor, and a digital-to-analog converter which is supplied with picture data for forming a P-in-P frame, having been produced from the self-picture data and the decoded data by the P-in-P processor, and which converts the supplied picture data into an analog signal and delivers the analog signal as an output.

Claims

1. A communication terminal which transmits and receives images through a communication line, comprising:

a communication unit which transmits or receives coded still picture data and coded moving picture data through said communication line, said coded still picture data being generated by carrying out a still picture encoding process on a digital image signal, and said coded moving picture data being generated by carrying out a moving picture encoding process on a digital image signal;

a digital image signal input unit which takes in a digital image signal that is a video signal on which analog/digital (A/D) conversion has been carried out,

a still picture encoding unit which carries out said still picture encoding process on a digital image signal inputted to generate encoded still picture data and outputs encoded data to said communication unit;

a moving picture encoding unit which carries out said moving picture encoding process on a digital image signal inputted to generate encoded moving picture data and outputs said encoded data to said communication unit;

a video switch which selectively inputs said digital image signal taken in by said digital image signal input unit either to said still picture encoding unit or to said moving picture encoding unit, wherein said video switch permits said communication terminal to selectively encode said digital image signal to one of said still picture encoding process or said moving picture encoding process as desired;

a still picture decoding unit which carries out a still picture decoding process on said coded still picture data received by said communication unit through said communication line to generate a digital image signal;

a moving picture decoding unit which carries out a moving picture decoding process on the coded moving picture data received by said communication unit through said communication line to generate a digital image signal;

an image synthesizing unit which selects two digital image signals among said digital image signal taken in by said digital image signal input unit, said digital image signal generated by said still picture decoding unit, and said digital image signal outputted from said moving picture decoding unit and synthesizes said two digital image signals thus selected and outputs them in a manner that respective images of the selected two digital image signals are simultaneously displayed on a display screen of a display device;

a Digital/Analog (D/A) converter which converts a digital image signal outputted from said image synthesizing unit into a video signal; and

an output unit which outputs the video signal from said D/A converter.

2. A communication terminal according to claim 1, wherein said image synthesizing unit synthesizes the selected two digital signals in a manner that one image represented by one digital image signal is displayed in overlap with another image represented by another digital image signal.

3. A communication terminal according to claims 1 and 2, further comprising:

a first storage unit which stores therein said digital image signal taken in by said digital image signal input unit;

a second storage unit which stores therein said digital image signal from said still picture decoding unit; and

a third storage unit which stores therein said digital image signal from said moving picture decoding unit,

wherein said image synthesizing unit generates a synthesized digital image signal and outputs it so that respective images of the selected two digital image signals are simultaneously displayed by controlling writing into and reading from said first to said third storages.

4. A communication terminal according to claim 3, wherein said still picture decoding unit and said moving picture decoding unit each comprise:

a frame memory used for the decoding process,

wherein said frame memory in said still picture decoding unit is used as said second storage unit, and said frame memory in said moving picture decoding unit is used as said third storage unit.

5. A communication terminal according to claim 1, further comprising:

a video signal input unit which takes in a video signal;

an Analog/Digital (A/D) converter which converts the video signal taken in by said video signal input unit into a digital image signal and inputs the digital image signal in said digital image signal input unit.

11. A communication terminal according to claim 2, further comprising:

a video signal input unit which takes in a video signal;

an Analog/Digital (A/D) converter which converts the video signal taken in by said video signal input unit into a digital image signal and inputs the digital image signal in said digital image signal input unit.

12. A communication terminal according to claim 3, further comprising:

a video signal input unit which takes in a video signal;

an Analog/Digital (A/D) converter which converts the video signal taken in by said video signal input unit into a digital image signal and inputs the digital image signal in said digital image signal input unit.

13. A communication terminal according to claim 4, further comprising:

a video signal input unit which takes in a video signal;

an Analog/Digital (A/D) converter which converts the video signal taken in by said video signal input unit into a digital image signal and inputs the digital image signal in said digital image signal input unit.

6. An image codec comprising:

a coded image data input unit which takes in coded still picture data and coded moving picture data, said coded still picture data generated by carrying out a still picture encoding process on a digital image signal, and said coded moving picture data generated by carrying out a moving picture encoding process on a digital image signal;

a digital image signal input unit which takes in a digital image signal that is a video signal on which analog/digital (A/D) conversion has been carried out;

a still picture encoding unit which carries out said still picture encoding process on a digital image signal inputted to generate encoded still picture data;

a moving picture encoding unit which carries out said moving picture encoding process on a digital image signal inputted to generate encoded moving picture data;

a video switch which selectively inputs the digital image signal taken in by said digital image signal input unit, either to said still picture encoding unit or to said moving picture encoding means, wherein said video switch permits said communication terminal to selectively encode said digital image signal to one of said still picture encoding process or said moving picture encoding process as desired;

a still picture decoding unit which carries out a still picture decoding process on the coded still picture data taken in by said coded image data input unit to generate a digital image signal;

a moving picture decoding unit which carries out a moving picture decoding process on the coded moving picture data taken in by said coded image data input unit to generate a digital image signal; and

an image synthesizing unit which selects two digital image signals among the digital image signal taken in by said digital image signal input unit, the digital image signal from said still picture decoding unit, and the digital image signal from said moving picture decoding unit, synthesizes the selected two digital image signals and outputs them in a manner that respective images of the selected two digital image signals are simultaneously displayed on a display screen of a display device.

7. A picture codec according to claim 6, wherein said image synthesizing unit synthesizes the selected two digital image signals and outputs them in a manner that one image represented by one digital image signal is displayed in overlap manner with another image represented by another digital image signal.

8. A picture codec according to claim 6, further comprising:

a first storage unit which stores therein the digital image signal taken in by said digital image signal input unit;

a second storage unit which stores therein the digital image signal outputted from said still picture decoding unit; and

a third storage unit which stores therein the digital image signal from said moving picture decoding unit,

wherein said image synthesizing unit generates a synthesized digital image signal, and outputs it so that respective images of the selected two digital image signals are simultaneously displayed on a display screen of a display device by controlling writing into and reading from said first to said third storages.

9. A picture codec according to claim 8, wherein said still picture decoding unit and said moving picture decoding unit each comprises:

a frame memory used for the decoding process,

wherein said frame memory in said still picture decoding unit is used as said second storage unit, and said frame memory in said moving picture decoding unit is used as said third storage unit.

10. A picture codec according to claim 6, further comprising:

an Analog/Digital (A/D) converter which converts a video signal inputted to a video signal input unit into a digital image signal to input the digital image signal into said digital image signal input unit; and

a Digital/Analog (D/A) converter which converts a digital image signal from said image synthesizing unit into a video signal to output the video signal to a video signal output unit.

14. A picture codec according to claim 7, further comprising:

an Analog/Digital (A/D) converter which converts a video signal inputted to a video signal input unit into a digital image signal to input the digital image signal into said digital image signal input unit; and

a Digital/Analog (D/A) converter which converts a digital image signal from said image synthesizing unit into a video signal to output the video signal to a video signal output unit.

15. A picture codec according to claim 8, further comprising:

an Analog/Digital (A/D) converter which converts a video signal inputted to a video signal input unit into a digital image signal to input the digital image signal into said digital image signal input unit; and

a Digital/Analog (D/A) converter which converts a digital image signal from said image synthesizing unit into a video signal to output the video signal to a video signal output unit.

16. A picture codec according to claim 9, further comprising:

an Analog/Digital (A/D) converter which converts a video signal inputted to a video signal input unit into a digital image signal to input the digital image signal into said digital image signal input unit; and

a Digital/Analog (D/A) converter which converts a digital image signal from said image synthesizing unit into a video signal to output the video signal to a video signal output unit.